<template>
  <!-- 底部 -->
  <div class="my-footer">
    <!-- 全选 -->
    <div class="custom-control custom-checkbox">
      <input v-model="isAll" type="checkbox" class="custom-control-input" id="footerCheck">
      <label class="custom-control-label" for="footerCheck">全选</label>
    </div>
    <!-- 合计 -->
    <div>
      <span>合计:</span>
      <span class="price">¥ {{allPrice}}</span>
    </div>
    <!-- 按钮 -->
    <button type="button" class="footer-btn btn btn-primary">结算 ( {{ allCount }} )</button>
  </div>
</template>

<script>
export default {
  props: {
    arr: {
      type: Array,
      required: true
    }
  },
  computed: {
    allPrice(){
      // return this.arr.reduce((total, item)=>{
      //   if(item.goods_state){
      //     return total+= (item.goods_count*item.goods_price)
      //   }
      //   return total
      // }, 0)
      let result = 0;
      this.arr.forEach(item=>{
        if(item.goods_state){
          result+=(item.goods_count*item.goods_price)
        }
      })
      return result
    },
    allCount(){
      return this.arr.reduce((total,item)=>{
        if(item.goods_state){
          total+=item.goods_count
        }
        return total  // 表示判断到不需要进行累加的商品时，直接把之前累加总数据返回给reduce即可
      }, 0)
    },
    isAll: {
      set(bool){
        this.arr.forEach(item=>{
          item.goods_state = bool;
        })
      },
      get(){
        return this.arr.every(item=>{
          return item.goods_state === true
        })
      }
    }
  }
}
</script>

<style lang="less" scoped>
.my-footer {
  position: fixed;
  z-index: 2;
  bottom: 0;
  width: 100%;
  height: 50px;
  border-top: 1px solid #ccc;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 10px;
  background: #fff;

  .price {
    color: red;
    font-weight: bold;
    font-size: 15px;
  }
  .footer-btn {
    min-width: 80px;
    height: 30px;
    line-height: 30px;
    border-radius: 25px;
    padding: 0;
  }
}
</style>